Side effects of chemotherapy

Chemotherapy drugs stop cancer cells dividing and growing. Some healthy cells also constantly divide and grow, so they can be affected too and this can cause side effects. As healthy cells can repair themselves quickly, side effects are usually temporary.

Chemotherapy affects people in different ways. Some people experience very few side effects while others have more. Different chemotherapy drugs have different side effects. Below are some of the more common ones.

Nausea and vomiting

Nausea can start straight after having the chemotherapy or up to several hours later. It can last for several hours or for as long as several days. It can usually be controlled or at least lessened with anti-sickness (also known as anti-emetic) drugs. If one combination of drugs does not help then others can be tried so always tell your hospital if you are struggling with nausea or vomiting. Some people find complementary therapies helpful, such as relaxation therapy, hypnosis or acupuncture.

Sore mouth

You may have a sore mouth or gums, or develop mouth ulcers or a dry mouth, so good mouth hygiene is important during treatment. Brush with a soft toothbrush and keep your mouth as moist as possible using alcohol-free mouthwashes and taking regular sips of water. If you already have tooth decay or gum disease, see your dentist so that these can be sorted out before treatment starts. Even if not, you may benefit from a routine dental check before chemotherapy.

Some people also find their sense of taste changes during chemotherapy, such as noticing a metallic taste in their mouth. If so, you could try experimenting to find foods you enjoy.

Hair loss

Hair loss can be one of the most distressing side effects of chemotherapy. It usually happens gradually and begins within two to three weeks of starting treatment, though it can be sudden. You may lose all your body hair, including eyebrows and eyelashes. Your hair should grow back after treatment has finished. Prolonged hair loss has been reported in a very small number of cases with some drugs. You can read more about this side effect in our booklet Breast cancer and hair loss

Bone marrow suppression

Chemotherapy can affect the bone marrow (the spongy material inside bones), meaning it is less able to make new blood cells. Before each course of chemotherapy you’ll have a blood sample taken. This is to make sure that cell levels are within safe limits for you to have the treatment. Sometimes blood cells can be affected to such a degree that treatment is postponed. Blood cells generally recover sufficiently within a week and treatment can start again.

White blood cells in particular can be affected by chemotherapy. They are responsible for fighting infection. Your nurses and doctors will give you advice about when your white blood cells may be low and about trying to avoid infection. Sometimes if a person’s white blood cell count is persistently low, an injection of a drug called G-CSF (granulocyte-colony stimulating factor) is given to help boost levels. This may also be given after subsequent chemotherapy cycles.

It is important to tell your GP (local doctor), or the hospital where you are having your chemotherapy treatment, as soon as possible if you develop any sign of infection such as a high temperature (over 38°C), feeling unwell or a sore throat.

Because chemotherapy can reduce the number of platelets (which help the blood to clot), you may find during your treatment you bruise more easily, have nosebleeds or notice that your gums bleed when you brush your teeth. You should tell your specialist team if you experience any of these symptoms. A platelet transfusion can be given, although this is rarely needed as platelet levels usually correct themselves over time.

Tiredness (fatigue)

You may become very tired during your treatment. Sometimes people having chemotherapy develop anaemia because of a low red blood-cell count. If you feel particularly tired, breathless or dizzy you should let your specialist team know. Although these symptoms can also be due to other causes, it is important to report them. Occasionally a blood transfusion may be necessary at some point during your treatment.

Even if your blood cell levels are normal, you may still be tired. Some people find that this fatigue lasts for several months after their treatment has finished. You may also find that the treatment affects your ability to concentrate or think clearly.

Sore eyes and runny nose

The drug 5FU used in some chemotherapy treatments can cause sore, gritty eyes and a runny nose. Eye drops may relieve the soreness. It is best to ask your specialist team or chemotherapy nurse to prescribe or advise on which eye drops to use. Eye drops bought over the counter are not always recommended.

Diarrhoea

You may have some diarrhoea (loose bowel movements) but medication will help control it. If you do, ask your specialist team or chemotherapy nurse for advice on what medication to take to help with this side effect. It’s especially important to tell them if you have profuse diarrhoea (often classed as more than four episodes of diarrhoea in a 24-hour period). Make sure you drink plenty of fluids to avoid dehydration.

Urinary problems

It’s important to drink plenty of fluids when you have your treatment as chemotherapy drugs (particularly cyclophosphamide) can irritate the lining of the bladder. Tell your specialist team or chemotherapy nurse if you notice any irritation or pain when going to the toilet.

Epirubicin will make your urine red for up to 24 hours after you have your treatment. This can be alarming but is a normal side effect of the drug.

Fertility

Some younger women find their periods become irregular or stop temporarily while they're having chemotherapy. Others find that they stop completely, which may indicate permanent infertility. The likelihood of this depends on your age and the drugs you are having.

Women around 35 and above are less likely to get their periods back after completing chemotherapy than younger women. If you’re concerned about your fertility, it's important to talk to your specialist team before treatment begins.

You may want to read our factsheet, Fertility issues and breast cancer treatment, which you can download from the right hand side of this page. 

Menopausal symptoms

Because chemotherapy can cause periods to become irregular, or stop temporarily or permanently, some women may also experience menopausal symptoms. These may include hot flushes, decreased sex drive and mood changes. Low levels of oestrogen (because of an early menopause) can also mean an increased risk of osteoporosis developing.

If you have concerns about your bone health or you have menopausal symptoms, talk to your specialist team or chemotherapy nurse. For more information, read our Menopausal symptoms and breast cancer factsheet.